Blade-mounted sensor apparatus, systems, and methods

ABSTRACT

In some embodiments, an apparatus and a system may include a tubular member; at least two interchangeable blades attached to the tubular member, the blades extendible radially outward to an extended position and retractable radially inward to a retracted position, wherein an outer surface of the blades is disposed at or below an outer surface of the tubular member when the blades are in the retracted position; and a plurality of sensors attached to the blades, the sensors to engage a circumferential portion of a borehole wall along the outer surface of the blades in an azimuthal direction when the blades are disposed downhole in the extended position, and to refrain from engaging the borehole wall when the blades are disposed downhole in the retracted position. Additional apparatus and systems, as well as methods, are disclosed.

BACKGROUND

Understanding the structure and properties of geological formations mayreduce the cost of drilling wells for oil and gas exploration.Measurements are typically performed in a borehole (i.e., downholemeasurements) in order to attain this understanding. For example, themeasurements may identify the composition and distribution of materialthat surrounds the measurement device downhole.

Measurement While Drilling (MWD) and Logging While Drilling (LWD) toolsare often used to make such measurements, to help determine whenhydrocarbon deposits are embedded in the surrounding formation.Temperature, pressure, and vibration may also be measured downhole,among other conditions. These measurements constitute data gathered bythe MWD/LWD tool, and may be sent up to the surface in real time (e.g.,in MWD), or retrieved at a later time (e.g., in LWD), after drillingoperations are completed. Such measurements can be made using sensors ortransducers, which may be fixed or movable, perhaps mounted along theMWD/LWD tool body, or on a probe that extends outwardly from the toolbody. Sometimes these probes are expensive to manufacture, or difficultto replace.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a blade-mounted sensor apparatus employed in twolocations on a drill string, according to various embodiments.

FIG. 2 provides perspective and top plan views of blades forming a partof a blade-mounted sensor apparatus, according to various embodiments.

FIG. 3 provides perspective and close-up views of a single blade,forming part of an apparatus, according to various embodiments.

FIG. 4 illustrates top and perspective views of an apparatus having fourblades in retracted and extended positions, respectively, according tovarious embodiments.

FIG. 5 illustrates top and perspective views of an apparatus having twoblades in retracted and extended positions, respectively, according tovarious embodiments.

FIG. 6 illustrates top and perspective views of an apparatus havingthree blades in retracted and extended positions, respectively,according to various embodiments.

FIG. 7 illustrates a side perspective view of a gear extensionmechanism, and a top plan view, with a perspective view inset of ahydraulic actuator extension mechanism, according to variousembodiments.

FIG. 8 illustrates a perspective view of an array of blade sets,according to various embodiments.

FIG. 9 illustrates side views of an apparatus, with blades in aretracted position, and an extended position to stabilize a drillstring, respectively, according to various embodiments.

FIG. 10 is a block diagram of apparatus and systems according to variousembodiments of the invention.

FIG. 11 is a flow chart illustrating several methods according tovarious embodiments of the invention.

FIG. 12 illustrates a wireline system, according to various embodimentsof the invention.

FIG. 13 illustrates a drilling rig system, according to variousembodiments of the invention.

DETAILED DESCRIPTION

Apparatus, systems, and methods are described herein that provide a newmechanism to mount sensors when making downhole measurements. Forexample, in some embodiments, the sensors can be attached to a drillcollar and/or a crossover substitute (also known as a crossover sub tothose of ordinary skill in the art). The sensors are mounted on bladesthat, upon activation, operate to extend radially outward toward theborehole wall, to come in contact with the surrounding formation. Thismode of operation enhances the coupling effect between the sensors andthe formation, often enhancing the accuracy of the associatedmeasurement. In some embodiments, multiple sensors are attached to asingle blade to offer different sensing services at particular location.The details of various embodiments will now be described.

FIG. 1 illustrates a blade-mounted sensor apparatus 100 employed in twolocations on a drill string, according to various embodiments. In thefigure, a drill string 110 is shown to include an MWD/LWD collar 120 anda crossover sub 130. The apparatus 100, including blades 150 can beformed as part of the collar 120, as well as the crossover sub 130. Aswill be shown in later figures, the apparatus 100 may comprise two ormore blades 150. In this figure, the apparatus 100 has four blades 150.

FIG. 2 provides perspective 120 and top plan views 220, 230 of bladesforming a part of a blade-mounted sensor apparatus, according to variousembodiments. These crescent-shaped blades 150 are shown in this figureto have a leading edge 240, and trailing edge 242. The leading edge 240slopes downward (underneath the substantially flat table 260) along adownward sloping surface 268, toward a substantially flat base 250. Thetrailing edge 242 rises above the substantially flat base 250, upwardalong an upward sloping surface 264, toward a peak 254, which terminatesat an edge of the substantially flat table 260. In many embodiments, thesubstantially flat table 260 and/or the downward sloping surface 268include an aperture 270 that forms a point of rotation when the blade150 is attached to a tubular member (not shown). The aperture 270 may beattached to the tubular member using a pin 274, for example.

In the figure, the top plan view 210 shows a set of four blades 150 in aretracted position, wherein the outer surfaces 272 of the blades 150combine to form a circle that is, in many embodiments, the same diameteras the tubular member to which the blades 150 are attached. This featureenables the blades 150, when in the retracted position, to conform tothe outer surface of the tubular member to which they are attached, bymatching the outer circumference of a drilling collar or crossover sub,for example (e.g., see FIG. 1).

FIG. 3 provides perspective and close-up views of a single blade 150,forming part of an apparatus 100, according to various embodiments. Hereit can be seen that the apparatus 100, comprising a tubular member 300and multiple blades 150, may be fabricated so that multiple sensors 310are mounted to each blade. For example, in the close up view of theblade 150, three different sensor types are shown: an electrode E, atransducer T, and a coil C. Many other sensor types may be supported,such as temperature, vibration, etc.

As shown in the figure, the blades 150 are movable from the retractedposition (not shown) to an extended position (shown). The blades 150 mayalso be constructed to as to be interchangeable, one for another. Thisallows a variety of sensing services to be provided with a single bladedesign. In some embodiments, as shown, the blades are also fabricated soas to be identical, making repair and substitution of the blades 150relatively easy. Individual blades 150 may include wiring connections320 on the inner surfaces 330 of the blades 150, providing electricalconnectivity to the attached sensors 310. In this figure, it can also beseen how the outer surface 272 of the blades 150 does not conform to theouter surface 340 of the tubular member 300 when the blades are in theextended position.

FIG. 4 illustrates top 410, 420 and perspective views 430, 440 of anapparatus 100 having four blades 150 in retracted and extendedpositions, respectively, according to various embodiments. Theoperational modes of the blades 150 thus include the retracted position(shown in view 430) and, after the blades have moved radially outward tocontact the borehole wall 450, the extended position (shown in view440). In view 430, it can also be seen how the outer surface 272 of theblades 150 conforms to and completes the outer surface 340 of thetubular member 300 when the blades are in the retracted position.

In many embodiments, the tubular member 300 that forms part of anMWD/LWD tool will rotate during drilling operations, and then rotationwill stop at some point. This may occur for a number of reasons,including to provide an opportunity to measure conditions in theborehole, such as formation pressure, seismic activity, etc. It is atthis point that an extension mechanism will be activated, to move theblades 150 from the retraction position (see view 430) to the extendedposition (see view 440), so that the blades 150 are contacting theborehole wall 450. Other numbers of blades 150 may be used in variousembodiments.

For example, FIG. 5 illustrates top 510, 520 and perspective views 530,540 of an apparatus 100 having two blades 150 in retracted and extendedpositions, respectively, according to various embodiments. Theoperational modes of the blades 150 again include the retracted position(shown in view 530) and, after the blades 150 have moved radiallyoutward to contact the borehole wall 450, the extended position (shownin view 540).

In another example, FIG. 6 illustrates top 610, 620 and perspectiveviews 630, 640 of an apparatus 100 having three blades 150 in retractedand extended positions, respectively, according to various embodiments.The operational modes of the blades 150 again include the retractedposition (shown in view 630) and, after the blades 150 have movedradially outward to contact the borehole wall 450, the extended position(shown in view 640).

FIG. 7 illustrates a side perspective view 710 of a gear extensionmechanism 715, and a top plan view, with a perspective view inset 730 ofa hydraulic actuator extension mechanism 735, according to variousembodiments. Thus, two possible extension mechanisms 715, 735, amongmany, can be used to extend and retract the blades 150 by urging theblades 150 radially outward, and rotating the blades 150 around the pins274. In some embodiments, extension activity may cease when the blades150 undergoing extension experience a sufficient counter-resistanceforce F, perhaps by coming into contact with a borehole wall, or ageological formation. Once contact is made, the sensors 310 can operateto provide measurement signals to other parts of a downhole measurementand data acquisition system.

FIG. 8 illustrates a perspective view of an array 800 of blade sets 810,according to various embodiments. This arrangement provides theflexibility of using different sensor groups 820′, 820″ arranged in anarray configuration along the longitudinal direction Z of the tubularmember 300. For example, the sensors in group 820′ may be ultrasonictransducers, and the sensors in group 820″ may be electrodes.

FIG. 9 illustrates side views 910, 920 of an apparatus 100, with bladesin a retracted position, and an extended position to stabilize a drillstring, respectively, according to various embodiments. In the firstview 910, the blades of the apparatus 100 are shown in the retractedposition. This position may be appropriate when drilling activity isongoing in the borehole 930.

In the second view 920, the apparatus 100 is acting as a passivecentralizer for the drill string 940. Thus, when the centerline 960 ofthe drill string 940 runs out from the centerline 970 of the borehole930, the blades 150 can be activated to extend toward the toward thewall 950 of the borehole 930, in order to passively centralize the drillstring 930 near the longitudinal location on the drill string 930 wherethe apparatus 100 is attached. Still further embodiments may berealized.

APPARATUS AND SYSTEMS

For example, FIG. 10 is a block diagram of apparatus 100 and systems1000 according to various embodiments of the invention. Here, it can beseen that the system 1000 may include a controller 1025 specificallyconfigured to interface with a controlled device 1070, such as anextension/retraction mechanism for the apparatus 100, a geosteeringunit, and/or a user display or touch screen interface (in addition todisplays 1055). The system 1000 may further include sensors 310, such aselectromagnetic transmitters and receivers, transducers, etc. (see FIG.3), attached to the blades of the apparatus 100. When configured in thismanner, the system 1000 can receive measurements and other data (e.g.,location and conductivity or resistivity information, among other data)to be processed according to various methods described herein.

A processing unit 1002 can be coupled to the apparatus 100 to obtainmeasurements from the sensors 310, and other components that may beattached to a housing 1004. Thus, in some embodiments, a system 1000comprises a housing 1004 that can be attached to or used to house theapparatus 100, and perhaps the controlled device 1070, among otherelements. The housing 1004 might take the form of a wireline tool body,or a downhole tool as described in more detail below with reference toFIGS. 12 and 13. The processing unit 1002 may be part of a surfaceworkstation, or attached to the housing 1004.

The system 1000 can include other electronic apparatus 1065, and acommunications unit 1040. Electronic apparatus 1065 (e.g.,electromagnetic sensors, current sensors, and other devices) can also beused in conjunction with the controller 1025 to perform tasks associatedwith taking measurements downhole. The communications unit 1040 can beused to handle downhole communications in a drilling operation. Suchdownhole communications can include telemetry.

The system 1000 can also include a bus 1027 to provide common electricalsignal paths between the components of the system 1000. The bus 1027 caninclude an address bus, a data bus, and a control bus, eachindependently configured. The bus 1027 can also use common conductivelines for providing one or more of address, data, or control, the use ofwhich can be regulated by the controller 1025 and/or the processing unit1002.

The bus 1027 can include instrumentality for a communication network.The bus 1027 can be configured such that the components of the system1000 are distributed. Such distribution can be arranged between downholecomponents such as the components attached to the housing 1004, andcomponents that are located on the surface of a well. Alternatively,several of these components can be co-located, such as on one or morecollars of a drill string or on a wireline structure.

In various embodiments, the system 1000 includes peripheral devices thatcan include displays 1055, additional storage memory, or other controldevices that may operate in conjunction with the controller 1025 or theprocessing unit 1002. The displays 1055 can display diagnostic andmeasurement information for the system 1000, based on the signalsgenerated according to embodiments described above.

In an embodiment, the controller 1025 can be fabricated to include oneor more processors. The display 1055 can be fabricated or programmed tooperate with instructions stored in the processing unit 1002 (forexample in the memory 1006) to implement a user interface to manage theoperation of the system 1000, including any one or more componentsdistributed within the system 1000. This type of user interface can beoperated in conjunction with the communications unit 1040 and the bus1027. Various components of the system 1000 can be integrated with abottom hole assembly, if desired, which may in turn be used to house theapparatus 100, such that operation of the apparatus 100, and processingof the measurement data, identical to or similar to the methodsdiscussed previously, and those that follow, can be conducted accordingto various embodiments that are described herein.

In some embodiments, a non-transitory machine-readable storage devicecan comprise instructions stored thereon, which, when performed by amachine, cause the machine to become a customized, particular machinethat performs operations comprising one or more features similar to oridentical to those described with respect to the methods and techniquesdescribed herein. A machine-readable storage device, as describedherein, is a physical device that stores information (e.g.,instructions, data), which when stored, alters the physical structure ofthe device. Examples of machine-readable storage devices can include,but are not limited to, memory 1006 in the form of read only memory(ROM), random access memory (RAM), a magnetic disk storage device, anoptical storage device, a flash memory, and other electronic, magnetic,or optical memory devices, including combinations thereof.

The physical structure of stored instructions may be operated on by oneor more processors such as, for example, the processing unit 1002.Operating on these physical structures can cause the machine to become aspecialized machine that performs operations according to methodsdescribed herein. The instructions can include instructions to cause theprocessing unit 1002 to store associated data or other data in thememory 1006. The memory 1006 can store the results of measurements offormation parameters, to include gain parameters, calibration constants,identification data, sensor location information, sensorextension/retraction force information, etc. The memory 1006 can store alog of the measurement and location information provided by the system1000. The memory 1006 therefore may include a database, for example arelational database. The processors 1030 can be used to process the data1070 to form images of cement surrounding a well, or the formationitself.

Thus, referring to FIGS. 1-10, it can be seen that many embodiments maybe realized. For example, an apparatus 100 may comprise a tubular member300 attached to at least three mechanically interchangeable blades 150,with multiple sensors 310 mounted on the blades.

In some embodiments, an apparatus 100 comprises a tubular member 300 andat least two interchangeable blades 150 attached to the tubular member300. The blades 150 being extendible radially outward to an extendedposition, and retractable radially inward to a retracted position. Theouter surface 272 of the blades 150 is disposed at or below an outersurface of the tubular member 300 when the blades 150 are in theretracted position. In some embodiments, a plurality of sensors 410 forma portion of the outer surface 272 of the blades 150, the sensors 310engaging a circumferential portion of a borehole wall 450 along theouter surface 272 of the blades 150 in an azimuthal direction when theblades 150 are disposed downhole in the extended position. The sensors310 refrain from engaging the borehole wall 450 when the blades 150 aredisposed downhole in the retracted position.

The tubular member may take the form of a drilling collar, or acrossover substitute device, or crossover sub. Thus, in someembodiments, the tubular member 300 comprises one of a drilling collar120 or a crossover sub 130.

The blades are often interchangeable, and may be identical. Thus, theinterchangeable blades 150 comprise identical blades in someembodiments.

There may be three or four blades (or more) attached to the tubularmember, occupying substantially equal portions of the circumferentialdistance around the outer surface of the tubular member. Thus, in someembodiments, the at least two interchangeable blades 150 comprise threeor four interchangeable blades 150, each of the blades 150 occupying asubstantially similar portion of a circumference of the tubular member300 when the blades 150 are in the retracted position (see views 420,520, 620 in FIGS. 4, 5, 6, respectively).

Each of the blades may overlap another blade when in the retractedposition. In some embodiments, each blade overlaps two other blades.Thus, in some embodiments, each of the blades 150 overlap at least oneother one of the blades 150 along the circumference of the tubularmember when the blades 150 are in the retracted position (see e.g.,views 420 and 440 in FIG. 4).

Gears and/or a variety of actuators 735 may be used to extend andretract the blades. Thus, in some embodiments, gears, electromagnetic,piezoelectric, shape memory alloy, or hydraulic actuators are attachedso as to couple the tubular member 300 to the blades 150 (see e.g.,views 710 and 720, and breakout view of the different types of actuators735, in FIG. 7).

Different sensor types may be attached to different blades, or the sameblades. Thus, in some embodiments, the plurality of sensors 310 compriseat least two different sensor types arranged on one of the blades (seee.g., inset view of FIG. 3). In some embodiments, the blade sensorscomprise one or more transducers (that provide a two-way conversion toand from electrical signals).

When in the retracted position, the ends of the blades may engage theends of other blades, in a mirrored fashion. Thus, in some embodiments,each of the blades 150 includes end pieces that engage end pieces ofother blades in a mirrored fashion (e.g., one end piece comprising theleading edge 240 and downward sloping surface 268 of one blade 150, andanother end piece comprising the trailing edge 242 and upward slopingsurface 264 of another blade 150) when the blades are in the retractedposition.

When in the retracted position, the outer surfaces of the blades maymeet the outer surface of the tubular member, to form a unified outersurface. Thus, in some embodiments, the outer surface 272 of the blades150 substantially conforms to the outer surface 340 of the tubularmember 300, to form a substantially continuous outer surface, when theblades 150 are in the retracted position (e.g., see view 430 in FIG. 4).

The blades may be attached to the tubular member using a rotating joint.Thus, in some embodiments, each of the blades 150 is attached to thetubular member 300 at a single point of rotation (e.g., using a pin274).

The tubular member may be attached to a number of pins that retain theblades via an aperture formed in each blade. Thus, in some embodiments,the single point of rotation comprises an aperture 270 in the blade 150extending in a longitudinal direction of the tubular member 300 andlocated on an interlocking portion of the blade (e.g., the edge 240, andthe downward sloping surface 268).

The blades may take a variety of forms, including that of a crescent.Thus, in some embodiments, each of the blades 150 is formed in acrescent shape (e.g., see blades 150 in view 230 of FIG. 2). Somesensors 310 operate best when a certain amount of standoff distance ismaintained between the sensor face and the borehole wall. Other sensorsoperate best when in full contact between the sensor face and theborehole wall is maintained. The crescent shape can be useful in manyembodiments precisely for this reason: there is the flexibility to mountsensors 310 on different locations of the outer surface 272 of the blade150, depending on the usage of each individual sensor 310. Thus, when aparticular crescent-shaped blade 150 is extended to engage the boreholewall, some sensors 310 mounted on the blade will be in direct contactwith the wall, and other sensors will be provided with the properstandoff between the sensor face and the wall.

More than one set of blades may be installed along the length of thetubular member, to form an array of blade sets. Thus in someembodiments, and apparatus 100 comprises multiple sets 810 of the atleast two interchangeable blades 150, each of the sets 810 attached tothe tubular member 300 at a different longitudinal location (along thelongitudinal axis Z).

A system 1000 may include a controller 1025 coupled to the multi-bladeapparatus 100, similar to or identical to the apparatus 100 describedpreviously. That is, in some embodiments the apparatus 100 isoperatively coupled to the controller 1025, with the apparatus 100comprising a tubular member 300 attached to at least two interchangeableblades 150. The blades 150 are extendible radially outward responsive toreceiving an extend command issued by the controller 1025, to anextended position, and retractable radially inward responsive toreceiving a retract command issued by the controller 1025, to aretracted position. An outer surface 272 of the blades 150 is disposedat or below an outer surface 340 of the tubular member 300 when theblades 150 are in the retracted position.

In some embodiments, the system 1000 further includes a plurality ofsensors 310 attached to the blades 150. The sensors 310 may form aportion of the outer surface 272 of the blades 150. The sensors 310 areattached to the blades 150 so as to engage a circumferential portion ofa borehole wall along the outer surface 272 of the blades 150 in anazimuthal direction when the blades 150 are disposed downhole in theextended position. The sensors 310 are also attached to the blades 150so as to refrain from engaging the borehole wall when the blades 150 aredisposed downhole in the retracted position. In some embodiments, aprocessing unit 1002 is coupled to the apparatus in lieu of thecontroller 1025, the processing unit 1002 programmed to issue thecommands to extend and retract. In some embodiments, the system 1000comprises both a processing unit 1002 and a controller 1025, with thecontroller 1025 receiving the extend and retract commands from theprocessing unit 1002, and the controller 1025 operating as an interfaceto a controlled device 1070 comprises extension/retraction mechanisms(e.g., gears, hydraulic actuators, etc.).

The multi-blade apparatus can operate as a passive stabilizer. Thus, insome embodiments, the tubular member 300 comprises a portion of a drillstring 940, and the apparatus 100 operates as a passive stabilizer tocentralize the drill string 940 when the blades 150 are in the extendedposition (e.g., see view 920 in FIG. 9).

When retracted, the outer surface of the blades may operate to form partof the outer surface of the tubular member. Thus, in some embodiments,the outer surface 272 of the blades 150 operate to complete the outersurface of the tubular member 300 when the blades are in the retractedposition (e.g., see views 430, 530, 630 in FIGS. 4, 5, 6, respectively).

The apparatus 100, system 1000, and each of their elements may all becharacterized as “modules” herein. Such modules may include hardwarecircuitry, and/or a processor and/or memory circuits, software programmodules and objects, and/or firmware, and combinations thereof, asdesired by the architect of the apparatus 100 and systems 1000, and asappropriate for particular implementations of various embodiments. Forexample, in some embodiments, such modules may be included in anapparatus 100 and/or system 1000 operation simulation package, such as asoftware electrical signal simulation package, a power usage anddistribution simulation package, a power/heat dissipation simulationpackage, a formation imaging package, an energy detection andmeasurement package, and/or a combination of software and hardware usedto simulate the operation of various potential embodiments.

It should also be understood that the apparatus 100 and systems 1000 ofvarious embodiments can be used in applications other than for loggingoperations, and thus, various embodiments are not to be so limited. Theillustrations of apparatus 100 and systems 1000 are intended to providea general understanding of the structure of various embodiments, andthey are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein.

Applications that may include the novel apparatus and systems of variousembodiments include electronic circuitry used in high-speed computers,communication and signal processing circuitry, modems, processormodules, embedded processors, data switches, and application-specificmodules. Such apparatus and systems may further be included assub-components within a variety of electronic systems, such astelevisions, cellular telephones, personal computers, workstations,radios, vehicles, geothermal tools, and smart transducer interface nodetelemetry systems, among others. Some embodiments include a number ofmethods.

METHODS

FIG. 11 is a flow chart illustrating several methods 1111 according tovarious embodiments of the invention. The methods 1111 may compriseprocessor-implemented methods, to execute on one or more processors thatperform the methods. For example, one embodiment of the methods 1111 maybegin at block 1121 with lowering the apparatus with retracted bladesinto a borehole, and extending the blades to engage the borehole wall atblock 1125.

In some embodiments, a method 1111 begins at block 1121 with lowering atubular member into a borehole while at least two interchangeable bladesattached to the tubular member are in a retracted position, with theblades being retractable radially inward from an extended position tothe retracted position. When in the retracted position, the outersurface of each of the blades is disposed at or below the outer surfaceof the tubular member.

The method 1111 includes, in some embodiments, extending the bladesradially outward into the extended position at block 1125 to engage, bythe outer surface of each one of the blades and a plurality of sensorsforming a portion of the outer surface of each one of the blades in anazimuthal direction, a circumferential portion of a wall of theborehole.

To extend the blades, a geared mechanism or an actuator can be used.Thus, in some embodiments, the activity at block 1125 further comprisesrotating a geared mechanism or activating an electromagnetic,piezoelectric, shape memory alloy, or hydraulic actuator attached to theblades.

The blades can be extended until a certain preselected amount ofresistive counter-force is measured with respect to one or more of theblades, or until a substantially equal counter-force is measured on eachblade. Thus, in some embodiments, the activity at block 1125 furthercomprises measuring a resistance force encountered by one or more of theblades, and ceasing to extend the blades when a preselected amount ofthe resistance force is measured.

Sensor data can be acquired from different sensor types. Thus, in someembodiments, the method 1111 comprises, at block 1129, acquiring sensordata from the plurality of sensors, wherein at least two differentsensor types are located on at least one of the blades.

The blades can be retracted to enable drilling operations, and then theblades can be extended to stabilize the tubular member, as well as theattached drill string. Thus, in some embodiments, the method 1111includes retracting the blades radially inward into the retractedposition at block 1131, and drilling into a geological formationsurrounding the borehole at block 1133, to extend the length of theborehole, using a drill string that includes the tubular member.

In some embodiments, the method 1111 may return to block 1125, toinclude extending the blades radially outward into the extended positionto stabilize the drill string within the borehole. In some embodiments,the method 1111 may continue from block 1133 to return to 1121, torepeat the activities designated therein, as well as in the other blocksof the method 1111.

It should be noted that the methods described herein do not have to beexecuted in the order described, or in any particular order. Moreover,various activities described with respect to the methods identifiedherein can be executed in iterative, serial, or parallel fashion. Thevarious elements of each method (e.g., the methods shown in FIG. 11) canbe substituted, one for another, within and between methods.Information, including parameters, commands, operands, and other data,can be sent and received in the form of one or more carrier waves.

Upon reading and comprehending the content of this disclosure, one ofordinary skill in the art will understand the manner in which a softwareprogram can be launched from a computer-readable medium in acomputer-based system to execute the functions defined in the softwareprogram. One of ordinary skill in the art will further understand thevarious programming languages that may be employed to create one or moresoftware programs designed to implement and perform the methodsdisclosed herein.

For example, the programs may be structured in an object-orientatedformat using an object-oriented language such as Java or C#. In anotherexample, the programs can be structured in a procedure-orientated formatusing a procedural language, such as assembly or C. The softwarecomponents may communicate using any of a number of mechanisms wellknown to those of ordinary skill in the art, such as application programinterfaces or interprocess communication techniques, including remoteprocedure calls. The teachings of various embodiments are not limited toany particular programming language or environment. Thus, otherembodiments may be realized.

WIRELINE AND DRILLING SYSTEMS

For example, FIG. 12 illustrates a wireline system 1264, according tovarious embodiments of the invention. FIG. 13 illustrates a drilling rigsystem 1364, according to various embodiments of the invention.Therefore, the systems 1264, 1364 may comprise portions of a wirelinelogging tool body 1270 as part of a wireline logging operation, or of adownhole tool 1324 as part of a downhole drilling operation. The systems1264 and 1364 may include any one or more elements of the apparatus 100and systems 1000 shown in FIGS. 1-10.

Thus, FIG. 12 shows a well during wireline logging operations. In thiscase, a drilling platform 1286 is equipped with a derrick 1288 thatsupports a hoist 1290.

Drilling oil and gas wells is commonly carried out using a string ofdrill pipes connected together so as to form a drilling string that islowered through a rotary table 1210 into a wellbore or borehole 1212.Here it is assumed that the drilling string has been temporarily removedfrom the borehole 1212 to allow a wireline logging tool body 1270, suchas a probe or sonde, to be lowered by wireline or logging cable 1274into the borehole 1212. Typically, the wireline logging tool body 1270is lowered to the bottom of the region of interest and subsequentlypulled upward at a substantially constant speed.

During the upward trip, at a series of depths, various instrumentsincluded in the tool body 1270 may be used to perform measurements(e.g., made by sensors 310 attached to the apparatus 100 shown in FIG.3) on the subsurface geological formations 1214 adjacent the borehole1212 (and the tool body 1270). The borehole 1212 may represent one ormore offset wells, or a target well. The blades in the apparatus 100 maybe extended and retracted as desired, perhaps to secure the position ofthe tool body 1270 in a more centralized position in the borehole 1212.

The measurement data can be communicated to a surface logging facility1292 for processing, analysis, and/or storage. The logging facility 1292may be provided with electronic equipment for various types of signalprocessing, which may be implemented by any one or more of thecomponents of the system 1000 in FIG. 10. Similar formation evaluationdata may be gathered and analyzed during drilling operations (e.g.,during logging while drilling operations, and by extension, samplingwhile drilling).

In some embodiments, the tool body 1270 is suspended in the wellbore bya wireline cable 1274 that connects the tool to a surface control unit(e.g., comprising a workstation 1254). The tool may be deployed in theborehole 1212 on coiled tubing, jointed drill pipe, hard wired drillpipe, or any other suitable deployment technique.

Turning now to FIG. 13, it can be seen how a system 1364 may also form aportion of a drilling rig 1302 located at the surface 1304 of a well1306. The drilling rig 1302 may provide support for a drill string 1308.The drill string 1308 may operate to penetrate the rotary table 1210 fordrilling the borehole 1212 through the subsurface formations 1214. Thedrill string 1308 may include a Kelly 1316, drill pipe 1318, and abottom hole assembly 1320, perhaps located at the lower portion of thedrill pipe 1318.

The bottom hole assembly 1320 may include drill collars 1322, a downholetool 1324, and a drill bit 1326. The drill bit 1326 may operate tocreate the borehole 1212 by penetrating the surface 1304 and thesubsurface formations 1214. The downhole tool 1324 may comprise any of anumber of different types of tools including MWD tools, LWD tools, andothers.

During drilling operations, the drill string 1308 (perhaps including theKelly 1316, the drill pipe 1318, and the bottom hole assembly 1320) maybe rotated by the rotary table 1210. Although not shown, in addition to,or alternatively, the bottom hole assembly 1320 may also be rotated by amotor (e.g., a mud motor) that is located downhole. The drill collars1322 may be used to add weight to the drill bit 1326. The drill collars1322 may also operate to stiffen the bottom hole assembly 1320, allowingthe bottom hole assembly 1320 to transfer the added weight to the drillbit 1326, and in turn, to assist the drill bit 1326 in penetrating thesurface 1304 and subsurface formations 1214.

During drilling operations, a mud pump 1332 may pump drilling fluid(sometimes known by those of ordinary skill in the art as “drillingmud”) from a mud pit 1334 through a hose 1336 into the drill pipe 1318and down to the drill bit 1326. The drilling fluid can flow out from thedrill bit 1326 and be returned to the surface 1304 through an annulararea between the drill pipe 1318 and the sides of the borehole 1212. Thedrilling fluid may then be returned to the mud pit 1334, where suchfluid is filtered. In some embodiments, the drilling fluid can be usedto cool the drill bit 1326, as well as to provide lubrication for thedrill bit 1326 during drilling operations. Additionally, the drillingfluid may be used to remove subsurface formation cuttings created byoperating the drill bit 1326.

In light of the foregoing discussion, it may be seen that in someembodiments, the system 1364 may include a drill collar 1322 and/or adownhole tool 1324 to house one or more systems 1000, including some orall of the components thereof. Thus, for the purposes of this document,the term “housing” may include any one or more of a drill collar 1322,or a crossover sub (see FIG. 1), or a downhole tool 1324 (each having anouter wall, to enclose or attach to blades to which magnetometers,sensors, fluid sampling devices, pressure measurement devices,transmitters, receivers, fiber optic cable, acquisition and processinglogic, and data acquisition systems, are attached). Many embodiments maythus be realized.

Thus, referring now to FIGS. 1-10 and 12-13, it may be seen that in someembodiments, the systems 1264, 1364 may include a drill collar 1322, acrossover sub (see FIG. 1) as part a downhole tool 1324, and/or awireline logging tool body 1270 to house one or more apparatus 100,similar to or identical to the apparatus 100 described above andillustrated in the figures. Any and all components of the system 1000shown in FIG. 10 may also be housed by the tool 1324 or the tool body1270.

The tool 1324 may comprise a downhole tool, such as an LWD tool or anMWD tool. The wireline tool body 1270 may comprise a wireline loggingtool, including a probe or sonde, for example, coupled to a loggingcable 1274. Many embodiments may thus be realized, and a list of some ofthem follows.

ADDITIONAL EXAMPLE EMBODIMENTS

In some embodiments, an apparatus comprises a tubular member and atleast two interchangeable blades attached to the tubular member. Theblades are extendible radially outward to an extended position andretractable radially inward to a retracted position. The outer surfaceof the blades is disposed at or below an outer surface of the tubularmember when the blades are in the retracted position.

In some embodiments, the apparatus further comprise a plurality ofsensors forming a portion of the outer surface of the blades, whereinthe sensors are used to engage a circumferential portion of a boreholewall along the outer surface of the blades in an azimuthal directionwhen the blades are disposed downhole in the extended position. Thesensors are attached to the blades so as to refrain from engaging theborehole wall when the blades are disposed downhole in the retractedposition.

In some embodiments, the tubular member comprises one of a drillingcollar, a crossover sub, or a bottom hole assembly.

In some embodiments, the at least two interchangeable blades compriseidentical blades. In some embodiments, some of the interchangeableblades comprise identical blades, and some of the interchangeable bladesdo not comprise identical blades.

In some embodiments, the at least two interchangeable blades comprisethree or four interchangeable blades. In some embodiments, each of theblades occupies a substantially similar portion of a circumference ofthe tubular member when the blades are in the retracted position.

In some embodiments, each of the blades overlap at least one other oneof the blades along the circumference of the tubular member when theblades are in the retracted position. In some embodiments, each of theblades overlap at least two other blades along the circumference of thetubular member when the blades are in the retracted position.

In some embodiments, gears, electromagnetic, piezoelectric, shape memoryalloy, and/or hydraulic actuators are used to couple the tubular memberto the blades.

In some embodiments, the plurality of sensors comprise at least twodifferent sensor types arranged on one of the blades. In someembodiments, the plurality of sensors on each blade are identical. Insome embodiments, the sensors comprise one or more transducers. In someembodiments, the transducers are attached to a single blade. In someembodiments, each transducer is attached to a different blade.

In some embodiments, each of the blades includes end pieces that engageend pieces of other blades in a mirrored fashion when the blades are inthe retracted position.

In some embodiments, the outer surface of the blades substantiallyconforms to the outer surface of the tubular member, to form asubstantially complete and continuous outer surface, when the blades arein the retracted position.

In some embodiments, one or more (or all) of the blades is attached tothe tubular member at a single point of rotation. In some embodiments,the single point of rotation comprises an aperture in the bladeextending in a longitudinal direction of the tubular member and locatedon an interlocking portion of the blade.

In some embodiments, each of the blades is formed in a crescent shape.Some embodiments comprise multiple sets of the at least twointerchangeable blades, each of the sets attached to the tubular memberat a different longitudinal location. The sets may be arranged to forman array of sonic transducers, or antennas, for example.

In some embodiments, a system comprises a controller and an apparatusoperatively coupled to the controller. In some of these embodiments, theapparatus comprises a tubular member attached to at least twointerchangeable blades, the blades being extendible radially outwardresponsive to receiving an extend command issued by the controller, toan extended position, and retractable radially inward responsive toreceiving a retract command issued by the controller, to a retractedposition. The outer surface of the blades is disposed at or below anouter surface of the tubular member when the blades are in the retractedposition. In some embodiments, the outer surface of the blades operateto complete the outer surface of the tubular member when the blades arein the retracted position.

In some embodiments, the system comprises a plurality of sensors forminga portion of the outer surface of the blades, wherein the sensors are toengage a circumferential portion of a borehole wall along the outersurface of the blades in an azimuthal direction when the blades aredisposed downhole in the extended position, and to refrain from engagingthe borehole wall when the blades are disposed downhole in the retractedposition.

In some embodiments, the tubular member comprises a portion of a drillstring, wherein the apparatus operates as a passive stabilizer tocentralize the drill string when the blades are in the extendedposition. This centralizing operation may occur when the tubular memberis used in a wireline operation, or a drilling operation, among others.

In some embodiments, a method comprises lowering a tubular member into aborehole while at least two interchangeable blades attached to thetubular member are in a retracted position. The blades are retractableradially inward from an extended position to the retracted position,wherein an outer surface of each of the blades is disposed at or belowan outer surface of the tubular member when the blades are in theretracted position.

In some embodiments, a method comprises extending the blades radiallyoutward into the extended position to engage, by the outer surface ofeach one of the blades and a plurality of sensors attached to the bladesin an azimuthal direction, a circumferential portion of a wall of theborehole. In some embodiments, the plurality of sensors form a portionof the outer surface of at least some of the blades in the azimuthaldirection.

In some embodiments, extending the blades further comprises rotating ageared mechanism or activating an electromagnetic, piezoelectric, shapememory alloy, or hydraulic actuator attached to the blades.

In some embodiments, a method comprises measuring a resistance forceencountered by one or more of the blades. The method may further includeceasing to extend the blades when a preselected amount of the resistanceforce is measured.

In some embodiments, a method comprises acquiring sensor data from theplurality of sensors, wherein at least two different sensor types arelocated on at least one of the blades. In some embodiments, the samesensors types are located on each of the blades.

In some embodiments, a method comprises retracting the blades radiallyinward into the retracted position. In some embodiments, the method mayfurther include drilling into a geological formation surrounding theborehole, to extend a length of the borehole, using a drill string thatincludes the tubular member. In some embodiments, the method may furtherinclude extending the blades radially outward into the extended positionto stabilize the drill string within the borehole. After reading theinformation disclosed herein, those of ordinary skill in the art willrealize that many other embodiments may be realized, but in the interestof brevity, these are not listed here.

CONCLUSION

In summary, the apparatus, systems, and methods disclosed herein differfrom conventional sensor mounting apparatus in that the sensor-mountedstructures may be fabricated as two, three, or four (or more) bladeswhich are crescent-shaped. Multiple sensors can be located on each bladeto provide different sensing services at any given circumferentiallocation around the wall of the borehole. The blades areinterchangeable, so that repairs are relatively inexpensive (e.g., asingle blade can be replaced, instead of an entire collar), and changesin sensing service can be made relatively easily as well.

Another difference in most embodiments is the mechanism used to couplethe sensors to the borehole wall. Due to the crescent shape of theblades, circumferential coupling is provided, rather than pointcoupling. This enhances the connection between the sensor and theformation. The proximity of the sensor to the borehole wall enable theacquisition of more accurate data, reducing noise created by the toolsand surrounding environment. In short, the overall construction of thevarious embodiments provides great flexibility, at relatively low cost.As a result, the value of services provided by an operation/explorationcompany may be significantly enhanced.

The accompanying drawings that form a part hereof, show by way ofillustration, and not of limitation, specific embodiments in which thesubject matter may be practiced. The embodiments illustrated aredescribed in sufficient detail to enable those skilled in the art topractice the teachings disclosed herein. Other embodiments may beutilized and derived therefrom, such that structural and logicalsubstitutions and changes may be made without departing from the scopeof this disclosure. This Detailed Description, therefore, is not to betaken in a limiting sense, and the scope of various embodiments isdefined only by the appended claims, along with the full range ofequivalents to which such claims are entitled.

Such embodiments of the inventive subject matter may be referred toherein, individually and/or collectively, by the term “invention” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single invention or inventive concept if morethan one is in fact disclosed. Thus, although specific embodiments havebeen illustrated and described herein, it should be appreciated that anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate embodiment.

What is claimed is:
 1. An apparatus, comprising: a tubular member; atleast two interchangeable blades attached to the tubular member, theblades extendible radially outward to an extended position andretractable radially inward to a retracted position, wherein an outersurface of the blades is disposed at or below an outer surface of thetubular member when the blades are in the retracted position; and aplurality of sensors attached to the blades, the sensors to engage acircumferential portion of a borehole wall along the outer surface ofthe blades in an azimuthal direction when the blades are disposeddownhole in the extended position, and to refrain from engaging theborehole wall when the blades are disposed downhole in the retractedposition.
 2. The apparatus of claim 1, wherein the tubular membercomprises one of a drilling collar or a crossover sub.
 3. The apparatusof claim 1, wherein the at least two interchangeable blades compriseidentical blades.
 4. The apparatus of claim 1, wherein the at least twointerchangeable blades comprise three or four interchangeable blades,each of the blades occupying a substantially similar portion of acircumference of the tubular member when the blades are in the retractedposition.
 5. The apparatus of claim 1, wherein each of the bladesoverlap at least one other one of the blades along the circumference ofthe tubular member when the blades are in the retracted position.
 6. Theapparatus of claim 1, further comprising: gears, electromagnetic,piezoelectric, shape memory alloy, or hydraulic actuators to couple thetubular member to the blades.
 7. The apparatus of claim 1, wherein theplurality of sensors comprise at least two different sensor typesarranged on one of the blades.
 8. The apparatus of claim 1, wherein eachof the blades includes end pieces that engage end pieces of other bladesin a mirrored fashion when the blades are in the retracted position. 9.The apparatus of claim 1, wherein the outer surface of the bladessubstantially conforms to the outer surface of the tubular member, toform a substantially continuous outer surface, when the blades are inthe retracted position.
 10. The apparatus of claim 1, wherein each ofthe blades is attached to the tubular member at a single point ofrotation.
 11. The apparatus of claim 10, wherein the single point ofrotation comprises an aperture in the blade extending in a longitudinaldirection of the tubular member and located on an interlocking portionof the blade.
 12. The apparatus of claim 1, wherein the sensors compriseat least one transducer.
 13. The apparatus of claim 1, wherein each ofthe blades is formed in a crescent shape.
 14. The apparatus of claim 1,further comprising: multiple sets of the at least two interchangeableblades, each of the sets attached to the tubular member at a differentlongitudinal location.
 15. The apparatus of claim 1, wherein at leastsome of the plurality of sensors form a portion of the outer surface ofthe blades.
 16. A system, comprising: a controller; and an apparatusoperatively coupled to the controller, the apparatus comprising atubular member attached to at least two interchangeable blades, theblades extendible radially outward responsive to receiving an extendcommand issued by the controller, to an extended position, andretractable radially inward responsive to receiving a retract commandissued by the controller, to a retracted position, wherein an outersurface of the blades is disposed at or below an outer surface of thetubular member when the blades are in the retracted position; and aplurality of sensors attached to the blades, the sensors to engage acircumferential portion of a borehole wall along the outer surface ofthe blades in an azimuthal direction when the blades are disposeddownhole in the extended position, and to refrain from engaging theborehole wall when the blades are disposed downhole in the retractedposition.
 17. The system of claim 16, wherein the tubular membercomprises a portion of a drill string, and wherein the apparatusoperates as a passive stabilizer to centralize the drill string when theblades are in the extended position.
 18. The system of claim 16, whereinthe outer surface of the blades operate to complete the outer surface ofthe tubular member when the blades are in the retracted position.
 19. Amethod, comprising: lowering a tubular member into a borehole while atleast two interchangeable blades attached to the tubular member are in aretracted position, the blades retractable radially inward from anextended position to the retracted position, wherein an outer surface ofeach of the blades is disposed at or below an outer surface of thetubular member when the blades are in the retracted position; andextending the blades radially outward into the extended position toengage, by the outer surface of each one of the blades and a pluralityof sensors attached to the blades in an azimuthal direction, acircumferential portion of a wall of the borehole.
 20. The method ofclaim 19, wherein extending the blades further comprises: rotating ageared mechanism or activating an electromagnetic, piezoelectric, shapememory alloy, or hydraulic actuator attached to the blades.
 21. Themethod of claim 19, further comprising: measuring a resistance forceencountered by one or more of the blades; and ceasing to extend theblades when a preselected amount of the resistance force is measured.22. The method of claim 19, further comprising: acquiring sensor datafrom the plurality of sensors, wherein at least two different sensortypes are located on at least one of the blades.
 23. The method of claim19, further comprising: retracting the blades radially inward into theretracted position; drilling into a geological formation surrounding theborehole, to extend a length of the borehole, using a drill string thatincludes the tubular member; and extending the blades radially outwardinto the extended position to stabilize the drill string within theborehole.